2,4,6-tripicryl-s-triazine

ABSTRACT

An explosive compound of 2,4,6-tripicryl-s-triazine and its method of preparation.

Unified some Pmem n 1 Dawns Aug. 28, 1973 1 1 2,4,6-TRlPICRYL-S-TRIAZINE[75] Inventor: Joseph CariDacons, Washington,

[73] Assignee: The United States of America as represenfiedj by fileSecretary of the Navy, Washington, DC.

[22] Filed: Nov. 20, 1968 [21] App]. No.: 779,308

[52] US. C1 260/248 CS, 149/92, 149/105 [51] Km. C1 C07d 55/12 [58]Field of Search 260/248 CS Primary Examiner-Leland A. SebastianAttorney-R. S. Sciascia and J. A. Cooke [57] ABSTRACT An explosivecompound of 2,4,6-tripicryl-s-triazine and its method of preparation.

5 Claims, No Drawings 1 2,4,6-TRIPICRYL-S-TRIAZINE BACKGROUND OF THEINVENTION This invention generally relates to high explosive aromaticnitro compounds and more particularly, to 2,4,6-tripicryl-s-triazine andits method of preparation.

Modern missile and space advances have established a definite need forthermally stable explosives, which are, nevertheless, sensitive toimpact and capable of delivering a large output of energy. As disclosedin applicants previous applications, Ser. No. 320,579, filed on Oct. 31,1963 and Ser. No. 685,736, filed on Nov. 27, 1967, now US. Pat. No.3,592,860, it has been found that certain polynitropolyphenyl explosivessuch as for example 2,2.2",4,44,6,66"-nonanitroterphenyl (NONA) and2,2",4,4',4",6,6',6"-octanitro-mterphenyl (ONT) exhibit desiredproperties of thermal stability and impact sensitivity. However, it washoped that other polynitropolyphenyl compounds would exhibit even betterexplosive properties than those shown by NONA and ONT. Further, it wasdesired to use a process of prepartion which would yield the explosivein sizeable quantities thus providing minimal production costs.

SUMMARY OF THE INVENTION Accordingly, it is an object of this inventionto provide an explosive compound having thermal stability and impactsensitivity.

Another object of the invention is to provide the explosive compound of2,4,6-tripicryl-s-triazine, hereinafter known as TPT.

Still another object of the invention is to furnish a method ofpreparation which yields sizeable production quantities of TPT.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The compounds of the inventionare prepared by the reaction of picryl halides with cyanuric chloride,2,4,6-trichloro-s-triazine, in the presence of a copper catalyst and anitrobenzene solvent. Pieryl halides which may be used are exemplifiedby picryl chloride, picryl bromide and picryl iodide. Of these halides,picryl bromide is preferred because it is a relatively inexpensivestarting material and it can be prepared in good yield from thenitration of bromobenzene in sodium nitrate-oleum or potassiumnitrate-oleum mixtures. The rates of reaction and yields of productswill, of course, vary depending on the particular picryl halide used.

The copper catalyst consists of different forms of finely divided coppersuch as mechanically pulverized copper (copper bronze) which may betreated by successive washing with acetone solutions of iodine andhydrochloric acid. Another form which may be used in lithographic bronzewhich contains 0.2-0.5 percent fatty acids.

Nitrobenzene is used as the solvent because it has a high boiling pointof about 210 C and because it permits cyanuric chloride to undergo theUllmann coupling reaction which previously was unknown for cyanuricchloride. The reaction mixture should be kept anhydrous to avoiddehalogenation of the starting materials. The reaction, itself, may becarried out under subnormal, normal or supemormal atmospheric conditionsand at temperatures ranging from about 90 C to the boiling point ofnitrobenzene.

The following examples are intended to illustrate methods of preparationof TPT, which utilize several characteristic reactants, however theseexamples are not intended in any way to limit the scope of the inventionbut are merely exemplary.

EXAMPLE I A solution of 18.5 g (0.1 moles) of cyanuric chloride is madein ml of dry nitrobenzene in a 500 ml 3- neck round bottom flask fittedwith a mechanical stirrer, an addition funnel, an air cooled condenserand a thermometer. To this is added 89.0 g (1.4 moles) of copper powder(*Purified Copper Powder from Matheson, Coleman and Bell and VenusNatural Copper Fine No. 44-F, U. S. Bronze Powders, 1nc., Flemington,New Jersey have been found suitable for this reaction.) with stirringand the temperature raised to C on an oil bath held in place by alaboratory jack. A volume of 20 ml of a solution of 118 g (0.4 moles) ofpicryl bromide in ml of dry nitrobenzene is then added rapidly. Thetemperature will drop to about 134 C and there is an immediate reactionindicated by a change in the color of the copper and a rise in thetemperature of the mixture to about 146 C. Heating is reduced bylowering the oil bath and the remainder of the picryl bromide solutionis added dropwise. The rate of addition is adjusted so as to requireapproximately 40 minutes for its completion. A temperature range of140-146 C is maintained during the addition and for 20 minutesthereafter. The reaction mixture is permitted to cool to ambienttemperature and then poured into 700 ml of methanol an cooled to 5 C.After filtering with suction through a glass fiber filter, the residueis thoroughly washed with cold methanol and dried in a warm oven. Thisresidue which contains TPT along with cuprous halides and unused copper,is digested in 1,000 ml of approximately 20 percent hydrochloric acidwith stirring for about 20 minutes, then filtered through a sinteredglass funnel. The resident on the funnel of TPI and copper, is washedfirst with dilute hydrochloric acid, then with water and finally withmethanol until the washings were nearly colorless. After drying on thefunnel for a few minutes, the filter cake is heated in three liters ofacetone to dissolve the TPT, treated with 25 g of Darco G 60 andfiltered. The amber filtrate is concentrated by rapid distillation withstirring until considerable crystallization has occurred and the volumeis about 400 ml. Methanol is then added at the about the same rate asthe distillate is removed until the temperature of the distillate is 62C. The mixture is then cooled to 5 C on an ice bath, the product wasrecovered by filtration, washed with cold methanol and dried in a warmoven. The yield was 60.7 g of a fine, very pale yellow crystalline solidwhich melted at 350-l C (d) after sintering at approximately 140 C.

In order to obtain high purity TPT, the above material is dissolved in2,000 ml of acetone and recrystallized as described above. On drying ina warm oven overnight, the product is 55.5 g of glistening pale yellowcrystals, mp 352-3 C after sintering at 140 C. The product is a solvatewhich on drying overnight at 140 C under reduced pressure loses itssolvent of crystallization leaving 50.4 g (72 percent yield) of porousopaque crystals, mp 352-30 C (d).

Anal. Calcd. For C,,H,,N,,O C, 35.3; H, 0.85; N, 23.6. Found: C, 35.37,35.45; H, 0.92, 0.89; N, 22.76, 22.80.

Mol. Wt. Calcd. For C H N O 714.18. Found: 727,693.

In order to determine the nature of the solvate, a twice recrystallizedsample, which had been dried at 80 C is heated at 280 C for 30 minutesand the gas evolved is vacuum transferred to the gas chromatograph. Theretention time identified the gas as acetone. Samples which had beendried overnight at 140 C show no acetone content. By measuring theweight loss on heating at 140 C for extended periods, it is found thatthe solvate contained 7.5 percent acetone and 92.5 percent TPTcorresponding to one mole of acetone per mole of TPT.

EXAMPLE II The procedure is similar to that of Example 1 except thatpicryl iodide is used instead of picryl bromide and the reactiontemperature is reduced to 125l30 C. The yield of this method ofpreparation is slightly greater than 80 percent. However, due to theinsolubility of cuprous iodide in hydrochloric acid, the method ofisolation is altered and the solids removed from a 0.05 mole run areextracted with 5 liters of hot acetone in three portions. This extractis then treated as in the picryl bromide preparation.

EXAMPLE Ill the amount of gas evolved from ONT at 280 C and NONA at 260C. The higher working temperature of TPT is accompanied by a higherimpact sensitivity of 93cm. as compared to 64cm. and 37cm. for ONT andNONA respctively. This measurement is actually an indication of thecompounds insensitivity because it requires a standard weight to fallfrom a higher distance (93cm.) in order to detonate the sample. However,these properties do not seem to effect the output of TPT, whichpreliminary tests indicate is not appreciably different from ONT andNONA.

Because of its great stability at high temperatures, this compound maybe effectively used where an explosive is desired in an elevatedtemperature environment. Examples of such uses include missile warheads,explosive and safety escape devices in spacecraft and supersonicaircraft as well as for oil well drilling.

Obviously many modifications and variations of the present invention arepossible in light of the above teachings. It is therefore to beunderstood that, within the scope of the appended claims, the inventionmay be practiced otherwise than as specifically described.

Having thus described the invention, what is claimed as new and desiredto be secured by Letters Patent of the United States is:

l. The compound 2,4,6-tripicryl-s-triazine.

2. The method of preparing the compound of claim 1 which comprisesreacting a picryl halide with cyanuric chloride under anhydrousconditions in the presence of nitrobenzene and a copper catalyst.

3. The method of claim 2 wherein the picryl halide is picryl bromide.

4. The method of claim 2 wherein the picryl halide is picryl chloride.

5. The method of claim 2 wherein the picryl halide is picryl iodide.

2. The method of preparing the compound of claim 1 which comprisesreacting a picryl halide with cyanuric chloride under anhydrousconditions in the presence of nitrobenzene and a copper catalyst.
 3. Themethod of claim 2 wherein the picryl halide is picryl bromide.
 4. Themethod of claim 2 wherein the picryl halide is picryl chloride.
 5. Themethod of claim 2 wherein the picryl halide is picryl iodide.